Method of and apparatus for compressing air and the like



Jan. 2 1945. A. M. THOMSEN 2,366,160

METHOD OF AND APPARATUS FOR COMPRESSING AIR AND THE LIKE Fil ed Dec. 18, 1939 2 Sheets r-Sheet 1 IN V EN TOR.

Jan. 2, 1945. A. M. THQMSEN 2,366,160

METHOD OF .AND APPARATUS FOR COMPRESSING AIR AND THE LIKE Filed Dec. 18, 1959 2 Sheets-Sheet 2 IN V EN TOR.

claims; e e

the drawings, Figures 1 and 2 illustrateftwo embodiments oftheinvention. In1 the, drawings Fig. 1, and 2 area pair of cylinders containing pistons 3 and 4 respectively.

ate ntecle'Jan. 2, 1945 UNITED STATES PATENT OFFICE 1 METHODOFANDnrrARATtiS FORhOM a rnnssmemnnp'rrmnmn Alfred Thomsen, SanFranciseojGalifl Application December 18, 1939,;seha1 1waetm73t l l ,2 Claims. .(C 230-49.)

My invention relates particularly to a a method 7 Both ends of eachcylinder communicate freely whereby itlbecomcspos'sible to compressfair or other gaseous'fluid by the application of heatand not as is new customary by'the application of s me form of mechanical energy. ,As compressed airfis in itself chiefly. utilized asa source of j mechanical pow it follows h thebroductidn of compressed air'by the application of direct heat thereto makes such compression also avail- .1-

able as a source of power if taken'in connection with a suitable prime mover. e

While methods of co ressing air and the like by the direct application of heat are old in the prior art, no ecoriornic successhas been achieved.

asyet. Faulty apparatus has been, largely responsible, but the greatest difficulty consists in getting efficient heat transfer betweentwo gaseous fluids separated from "one anotherby a con- 1 ducting wall. e y To overcome thisdifiiculty I heat the fluid only by direct combustion of fuel therein, in which case a 100%.perfect furnace effect isproduced. LikewiseI cool said fluid only by the instrumentality of direct contact with water, and if this latter medium be maintained at temperatures excess 0ff212 F. then, manifestly, such cooling will be accompanied by the generation of the eorresponding amount ,of steam, said steam cornmingling with the working fluid. To achieve heat economy I avail myself of heat recuperators that functionon the wellknownstirling cycle;

[This is illustrated in Fig. land Fig. 2 which represent in a schematic manner the functions bustion of fuel in 'the fluid and cooling by a.

water spray areindicated, as is the transfer of a confined body of 'air, or other gaseous .fiuid,

strumentality of the pistons 3 and 4. Th mov mgnum passesthrough the indicated regeneraresentiairreceives connected to the cylinders by tors, on which the efliciency of the heat trans- 5 ferdepends, and thus becomes compressed, ul-

timately flowing into the. receivers. mg of the effect is indicated by the use of two Compoundt units, the working fluidbeing passed from one tb'the other. er detail later on.

In the preferred version of my invention as illustrated in the drawings I take advantage of all these innovations, and consideration of the same may therefore be undertakenryI do not necessarily limit myself to the procedure indi-j Both figures are explained in greatbatedtherein but I give;itonly as a preferred version of the wider scope which appears in my other of therespective cylinder. i In Fig. 1 both pistons arerepresented in midwith one another through therecuperat'ors 5 and. 6 an'dthe combustion chambers "1 and '8, so that i there isfsubstantially the same pressure onuboth sides of each piston. Such pistons, theoretically,

do no actual work but'in'erely serve as the means whereby theworkinghuid within the cylinders to the l is transferred alternately from one end stroke and the arrows indicate the direction of their travel; 9 and I10 are means for injecting fuel, with auxiliary airif desired, the working fluid withinjthe cylinders b'eingheatedl by the combustion of saidffiiejl. As the weight of the 1 pistons, with their superlmpbsed b'urdenof water H and IZ is considerable, they are advantageous-' 1y connected andmoved in as hereinjindicated.

in the cylinderaff'ected, it can manifestly be supplied "from 'ent'irelyoutside sources; This, however, is only a matter of convenience and, isno't 9 mandatory as each cylindereonstitutes a separate entity and the pistoncould be moved with- "out any regardto sequence "with the next in the series, if there bea seriesand not merely a single Water sprays l3 and "llareu sed on the cool sides of the pistonsto control the temperature differential between top and bottom sections of each cylinder, andtogether with the. accumulated waterup'on the top of (each piston they "serve to cool the cylinderwalls. il5I6-l1re'pare actuated by the workingifiuid and also "'controlythe flow of the working fluid, i. e., air undergoing compression, toand fromsaid receivers.

a A working strokerconsist's of the, following series of operations. In the cylinder 2 the piston is shown as descending. Such motion transfers the air from the spacebelow thepistoh to the space above the piston. {The displaced air passes upwardsthrough the heat recuperatoriwhere it drops :much of its heat. The heat not thus absorbedis removed'byth'e water spray l3, by the [cooling effect of .the water lupo'n ithe piston, and

by the coolwalls.

1 The :pistonis now at thebottomof its stroke but at some place during the strokethe change in temperat re of the working fluid caused a sufficient drop inpressure to actuate the valves; 20-2|;. .At the start of the strokevthis closed valve 20, and at.a laterpointitopened valve 2!" andto equalize the pressure, cool air fiowedfrom the receiver llfintothe cylinder 2. I On 'thefupstrol'fe 'cbndi'tib'nsare reversed. The

air above the piston is now to be transferred to the opposite end of the cylinder. In passing through the recuperator much of the stored heat from the former stroke is re-absorbed, and additional heat is supplied by the combustion of fuel injected at 9 and by stored heat in the combustion chamber 1.

When the piston has reached the top of its 73 stroke, substantially all of the-working fluid is below the piston for compared to the volume of the cylinder the' space within recuperator and combustion chamber is quite small. (For the' sake of clarity, the size of recuperator and combustion chamber, relative to that of the cylinder, has been exaggerated.) There has therefore been an increase in pressure according to the law of Charles. This closed valve 2| at the outset, and when the pressure within the cylinder 2 became greater than in the receiver Hi, the valve 20 opened and the surplus air'and combustion products was discharged into receiver l6.

In the drawings the valves are shown as operated by the change in pressure of the working fluid, but this is only byway of illustration as they could evidently be worked by the engine itself through proper valve motions.

Meanwhile, as pistons .3 and 4 are moving in counterbalance with one another, an identical set of operations has been performed in cylinder 1, and an amount of air equivalent to that which has been transferred from I! to [B has also been transferred from 16 to 15, each transfer being at a correspondingly higher pressure. It is selfevident that such compounding, starting with air at atmospheric pressure, can be repeatedas long der, 3|, containing a tight piston 32.

as said air will support combustion of fuel within a highly heated chamber. Even after this point has been reached such compounding can be continued by the use of auxiliary air introduced at 9 together with thefuel supply.

In Fig. 1, only two cylinders are represented, air entering at22 and being discharged at 23, but it is self-evident that any number of such cylinders could be assembled into a battery and that the pressure of the incoming and outgoing air could be adjusted entirely at the will of the operator. Motion to thepistons 3 and 4 is indicated as conveyed through the instrume'ntality of the rocker arm 26, which in turnis moved by the electric motor 29, the pinion of same, 28, a

engaging the toothed sector 21 which is attached to the rocker arm. This method of moving the pistons is purely schematic and is not, claimed, it being evident that any number ofother ways to produce such motion could be substituted.

If the compressed fluid is to be used at once in a prime mover then it will be evident that it would be advantageous to permit the so-called cool end of the cylinder to remain at such a temperature that cooling is produced by the conversion of the sensible heat of .the fluid into latent heat of evaporation of water. In this case no discharge of water would be required from the cylinder to compensate for that added by the spray but instead steam would be formed and such steam would leave commingled with the working fluid proper, and would in fact become a component thereof. The heat otherwise wasted in the cooling water wouldthus perform useful work in the prime mover. 1

It will likewise be evident that the alternate rise and fall of pressure within such a pair of vessels as herein'described can be used to impart motion to a piston within an enclosed cyl- I 2,866,160 V fv inder by simply connecting the oppositeends of said cylinder with the cooledv ends of the respective vessels, thus converting at once the heat energy of the working fluid into mechanical work. This is indicated and illustrated in Fig. 2 of the drawings. The same reference numbers have been used throughout as in Fig. 1, before described, and the entire operation is identical. It

will be seen that the cool ends of the respective cylinders, l and 2, connect by means of the pipes 32 and 33 with opposite ends of a Working-cylin- As the pressures in I and 2, rise and fall alternately they will manifestly impart motion to said piston which can be connected to an type of mecha nism for the conveyance of power by its attached piston rod 30. As in the case of Fig. 1, the means by which the pistons 3 and 4 are moved is purely schematic and not claimed, a balance wheel, 26, being'substituted for the former rocker arm. .Meanwhile compressed air will be vented at the valves l8 and 2!), while air will be aspirated at the valves I9 and 2|. I

I-Iaving thus fully explained my process and the types of machinery suitable for use in said process,

I claim:

1. In an apparatus for compressing air by the direct application of heatthe combination of a series of units each, one of which isv operating under H 7 identical and each unit consisting of a combination of a vessel with a movable separating member dividing same into two parts; a free ine terconnection between said two parts containing a heat recuperator; means for heating the air at oneend of said recuperator by the combustion of fuel therein; means for cooling said air at the opposite end of the recuperator by direct contact with water; suitable valves for the discharge of compressed air and for the admission of fresh air to replace. such discharge as the pressure rises and falls in accordance with the motion of the movable member; and, means for imparting motion to said movable memberLeach unit of said series, except the first and last units of the series, receiving air from the next lower in pressure of the series and discharging air to the next higher in the series; additional means being supplied for the introduction of auxiliary air of combustion where needed.

' 2. The method of compressing air by the vdirect application of heat which comprises; transferring a confined body of saidair alternately from a heated to a cooled portion of' the confining Vessel; storing a part of the heat resident in the hot air in its passage to the cool portion of said vessel and returning said heat again ,to the air in its. return travel to the former location; adding additional heat to said air by'burning fuel therein at the hot end and converting the residual heat in said air intolatent heat of evaporation of water by direct contact with'wat'er at the cool end, said water being maintained at temperatures in excess of 212. F., cooling thus being effected by conversion of the'sensible heat in the working'fluid into latent heat of evapora tion while 'the steam thus being continuously formed escapes as a component of the working fluid; meanwhile venting air under pressure and admitting fresh air to takeits place, alternately, as the pressure rises andfalls on each alternate transfer. I I M. 'IHOMSEIN.

different pressure but being otherwise 

